Extruded clay or ceramic tile, sometimes called quarry tile, is commonly used in institutional and non-institutional kitchens such as restaurants because it is relatively inexpensive, durable, and has relatively low porosity. Quarry tile is made from natural clays with the composition being approximately 50% hard particles (silicon) and the other 50% soft particles (clay components). When the clay tile is fired, it develops a pervious glaze-like coating which encapsulates pores under the surface. Because of the pervious nature of the surface, these pores collect and entrap various soils that are extremely difficult to clean thoroughly.
During the manufacturing process of quarry tile, a natural surface roughness may be created consisting of hard, microscopic peaks of silica and inert clays. The surface texture or roughness coupled with the surface porosity provides the tile with an optimum static coefficient of friction (traction). New quarry tile tends to be slip-resistant, and some tiles feature anti-slip properties such as added grit, grid patterns, or a rougher surface texture. However, even the anti-slip tile becomes worn and soiled over time and becomes slippery and potentially dangerous. After a short time, the quarry tile receives abrasion and surface wear due to foot traffic, soils, and daily surface cleaning. The microscopic peaks may become polished or worn down, leading to flat surface areas. These worn areas result in a lower static coefficient of friction and create a potentially slippery floor surface. In addition, frying, grilling, and sautéing create airborne grease, which causes a potentially hazardous film to develop on the tile. Despite daily cleaning, there if often a buildup of soil and grease over time, and a quarry tile floor can become saturated with grease and continue to stay slippery despite routine cleaning.
Hard surface cleaners useful in institutional and non-institutional environments may take any number of forms. An example of such a cleaner is an aqueous cleaner formulation that can be neutral, acidic, or alkaline in pH when diluted to create a use solution. Aqueous neutral, acidic, or alkaline cleaners in use solutions are typically formulated using a major proportion of an aqueous diluent and a minor proportion of the cleaner. Cleaners having a neutral pH or an alkaline pH effectively remove fresher grease soils, and cleaners having an acidic pH effectively remove polymerized grease soils. An example of an acidic cleaner formulation useful in cleaning soils comprising food residue is disclosed in U.S. Pat. No. 6,432,906, which is incorporated by reference herein. An example of a basic (alkaline) cleaner formulation useful in cleaning soils comprising food residue is disclosed in U.S. Pat. No. 5,474,698, which is incorporated by reference herein.
U.S. Pat. No. 5,797,986, which is incorporated by reference herein, discloses a method of cleaning a floor using a first cleaner with a pH departing from neutral followed by a second cleaner with a complementary pH. In one aspect, the first cleaner is an acidic cleaner and the second cleaner is a basic cleaner. In another aspect, the first cleaner is a basic cleaner and the second cleaner is an acidic cleaner. This method provides optimal cleaning.
The cleanliness of hard surfaces such as floors is characteristic of a substantially improved coefficient of friction (hereinafter “COF”). A COF greater than about 0.4 connotes a non-slip surface of substantially improves safety when compared to slippery soiled surfaces. By increasing the coefficient of friction (traction) and reducing floor slipperiness, dangerous accidents can be reduced.